1. Field
One embodiment of the invention relates to a head used in a disk drive such as a magnetic disk drive, a head suspension assembly provided with the head, and a disk drive provided with the head suspension assembly.
2. Description of the Related Art
A disk drive, e.g., a magnetic disk drive, comprises a magnetic disk, spindle motor, magnetic head, and carriage assembly. The magnetic disk is disposed in a base. The spindle motor supports and rotates the disk. The magnetic head writes and reads information to and from the disk. The carriage assembly supports the head for movement relative to the disk. The carriage assembly comprises a pivotably supported arm and a suspension extending from the arm. The head is supported on an extended end of the suspension. The head comprises a slider attached to the suspension and a head portion on the slider. The head portion is constructed including a reproducing head for reading and a recording head for writing.
The slider comprises a facing surface or air bearing surface (ABS) that faces a recording surface of the magnetic disk. The slider is subjected by the suspension to a predetermined head load that is directed to a magnetic recording layer of the disk. When the magnetic disk drive is powered, airflow is produced between the rotating disk and slider. Thereupon, a force (positive pressure) to fly the slider above the recording surface of the disk acts on the facing surface of the slider, based on the principle of air lubrication. By balancing this flying force and head load, the slider is flown above the recording surface of the disk with a gap therebetween. There is known a disk drive in which a negative-pressure cavity or groove producing dynamic pressure is formed near the center a facing surface of a slider, in order to prevent fluctuation of the flying height of the slider.
Specifically, this slider comprises a negative-pressure groove in a central part of an ABS, leading pad on the inflow end side of the slider, side pads extending from the leading pad toward the outflow end, and skirt portions extending from the side pads, individually, and a magnetic head is disposed on the trailing pad (e.g., Jpn. Pat. Appln. KOKAI Publication No. 2008-16068).
If the pressure within the disk drive with the magnetic head constructed in this manner is reduced by change of environment or the like, the flying height of the head may be reduced so that the head touches down or contacts a surface of a disk, in some cases. If the magnetic head contacts the disk, it vibrates and repeats touchdown and takeoff. Consequently, there is a possibility of the head being finally adhered to the disk surface.